Window frames: cumulative, first and last

Define exactly what a window sees per row. Compare same-day orders, build a stable cumulative total and explicitly request first and last of the whole partition.

A frame is the rows a function sees for the current row. ROWS with unique ordering builds a row-by-row cumulative value. With ORDER BY, the default RANGE through CURRENT ROW includes peers; LAST_VALUE need not mean partition end.

Window frames: cumulative, first and last: A frame is the rows a function sees for the current row. ROWS with unique ordering builds a row-by-row cumulative value. With ORDER BY, the default RANGE through CURRENT ROW includes peers; LAST_VALUE need not mean partition end.